Launching an insurgency campaign from the far right, Tennessee Rep. Joe Carr announced Tuesday that he's challenging U.S. Lamar Alexander in next year's Republican primary, giving tea party activists at least one candidate to take on Tennessee's longest-serving statewide politician.

But at this point, he isn't necessarily the tea party's consensus pick and more candidates could surface in the weeks ahead. He's also lost his campaign director from his previous race.

Carr, R-Lascassas, has ditched his primary campaign against embattled District 4 Congressman Scott DesJarlais, with plans to transfer funds raised for that contest to his new one. The frustration of Tennessee voters, he said, compelled him to target a two-term U.S senator he called the state's "most liberal" of Tennessee's Republican delegation in Washington.

That senator's public service goes back more than three decades, and he's a well-financed, 73-year-old incumbent who enjoys the support of nearly the state's entire Republican establishment.

"We're taking on a Goliath -- we know we are," Carr told conservative talk show host Ralph Bristol of 99.7 WTN, where he chose to make the announcement, the morning after The Tennessean first reported on his candidacy.

Alexander's campaign responded within minutes of the hour-long radio appearance, touting the senator's "conservative voting record" and pointing to his National Rifle Association, National Right to Life support and chamber of commerce backing.

"He will continue to do his best to use his experience and conservative principles to solve problems and get results for the people of Tennessee."

Carr, who had struggled to compete financially against another opponent, state Sen. Jim Tracy, R-Shelbyville, in the congressional race, referenced a conversation with Nashville automobile mogul Lee Beaman that helped tilt his switch. He said he arrived at this decision over the last few weeks, even though he acknowledged Alexander's popularity. Carr said Beaman is his campaign chairman.

"Lamar is popular but there is a disconnect with his popularity to the way he has voted," Carr said, pointing to his vote for comprehensive immigration reform, among others.

"The bottom line is this: If Lamar Alexander is voting for Barack Hussein Obama 62 percent of the time, he is voting against Tennesseans."

Carr's candidacy throws a wrench into the 2014 Republican primary, but it's still unclear whether he boasts the organization, financing or backing to mount a viable campaign.

With his entry, Carr brings with him approximately $300,000 that he had raised for his congressional race, one-tenth of the $3 million Alexander raised. On Tuesday, Carr set the fund-raising bar for his Senate race at between $5 million and $6 million, referencing Washington-based conservative political action committees that could help get him there.

The Senate Conservatives Fund, however, which has given millons of dollars to tea party Senate candidates in others states, but is looking for someone other than Carr.

"We're a little concerned about Carr," said the group's executive director, Matt Hoskins. "If he couldn't get traction in the House race, he probably won't get traction in the Senate race either.

"If Carr doesn't catch fire and a more compelling conservative enters the race, he could be the spoiler that helps re-elect Lamar Alexander. That's something we want to avoid."

Carr's announcement follows weeks of speculation on a possible tea party candidate that might emerge to appeal to the far right of the Republican Party.

Tea party groups have organized a series of "vetting" sessions, beginning Aug. 31 in Nashville, to endorse a challenger to Alexander. Knox County Mayor Tim Burchett and former Williamson County GOP chairman Kevin Kookogey have been discussed as other possible tea party contenders. Carr has said he plans to attend those events.

"I'm not endorsing anybody at this point," Nashville Tea Party President Ben Cunningham said. "I'm certainly glad that somebody of Joe's caliber has stepped forward. That's of course what we were all hoping would happen -- that good candidates would offer themselves.

"We have other people that will probably step forward, too," he said. "We're going to have some excellent choices."

Kookogey did not respond to an email asking whether he's still weighing a run.

Carr's campaign got off to a somewhat rocky start on Tuesday, misspelling Senate as "Sentate" on his campaign website. There was also news that former Tennessee GOP chairman Chip Saltsman, who had joined Carr's congressional race this year as campaign director, wouldn't be taking the same role in his Senate race.

"I signed up to help you run for Congress, not the Senate," Saltsman said in a letter to Carr announcing his resignation.

"It is because of Lamar Alexander that people like you have the honor of serving in the majority of the state legislature," he added. "I am honored to support Lamar Alexander for re-election."

Carr is hoping to follow in the footsteps of Senators Ted Cruz of Texas, Rand Paul of Kentucky and Mike Lee of Utah as tea party candidates who have captured Senate seats. Others have challenged longtime incumbents and won, but then lost in the general election.

The Tennessee Republican Party has a policy of not getting involved in party primaries, according to its spokesman, Brent Leatherwood.

Carr, a fierce advocate of the Second Amendment and frequent sponsor of bills that have infuriated immigration reform advocates, was elected to his House seat in 2008. He was lagging behind Tracy financially in the race to knock off DesJarlais.

Carr raised $100,225 during the most recent financial quarter, compared to $296,393 for Tracy. Meanwhile Tracy's cash-on-hand tally is $656,201, more than double Carr's tally.

Still, Carr said he was in a "unique and very genuine position to win that race."